Buyers from around the world have gathered south of Auckland for the national yearling sales at Karaka.

Prime Minister John Key will open New Zealand Bloodstock’s 86th National Yearling Sales Series on Monday.

The six-day event offers 1444 horses and a three-quarter brother to So You Think is among the headliners.

The colt, offered in the Windsor Stud Park draft, is out of La Souvenir, a daughter of So You Think’s dam Triassic.

“He is a good sized horse and is a very strong and well put together colt,” said stud manager Rodney Schick.

“He ticks all the boxes on type and is hard to fault so we expect him to be very popular.”

The two-day premier sale is followed by the three-day Select Sale of 620 horses and then the one-day Festival Sale of 308 horses.

In 2011, buyers from 11 countries bought 1050 yearlings for more than $NZ88 million ($A68 million).

This year, good money can be expected for the top lots but the world economic uncertainties could test the strength of the overall market.